Divers spent a grim day bringing body after body out of the sunken ferry Sewol.

They are lifted onto a dock -- slowly, gently -- and then shrouded with a blanket.

Some of the police officers standing guard wipe away tears as the bodies are carried past.

At least 108 people have died and 194 others remain missing. Many of them are students and teachers on a field trip from a high school near Seoul, the South Korean coast guard said Tuesday.

Although 174 people were rescued soon after the vessel sank Wednesday, no survivors have been found since.

"The conditions are so bad, my heart aches. We're going in thinking there may be survivors. When we have to come back with nothing, we can't even face the families," said Bard Yoon, a rescue diver.

Speaking for the families and much of her country, South Korean President Park Geun-hye likened the actions of the captain and some crew members of the Sewol to murder, as police made more four arrests.

The captain of the South Korean ship, Lee Joon-seok, is already facing a series of criminal charges for his role in the sinking.

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"The actions of the captain and some of the crew are absolutely unacceptable, unforgivable actions that are akin to murder," Park said Monday in comments released by her office. She said she and other South Koreans were filled with "rage and horror."

The latest arrests of crew members bring the total number detained to seven as authorities investigate what went wrong on the ship as it sailed toward a popular holiday island.

Chonghaejin Marine, which operated the ferry, has posted an apology on its website.

"We pray for the Sewol victims who lost their precious lives due to the accident. We prostrate ourselves before the victims' families and beg for forgiveness.

"We apologize to all the people who are grieving for the loss of their loved ones. Also, we apologize to the people who had injuries, major or minor, due to this accident. We wish them a speedy recovery," read the statement. It was unclear when exactly it was posted.

"We will try our best to rescue the missing people quickly and we pray with all our hearts that there will be survivors.

"Once again, we beg for forgiveness from the victims' families and pray for the dead."

Dramatic dialogue

President Park's strong words came after more details emerged over the weekend about the chaos and confusion aboard the doomed ferry as the disaster unfolded in the cold waters of the Yellow Sea off South Korea's southwest coast.

A radio transcript released by authorities suggested that passengers on the ship couldn't reach lifeboats to escape because the ship tilted so quickly that it left many of them unable to move.

Capt. Lee has defended his order to delay the evacuation of the ferry.

"It is a fairly fast current area, and the water temperature was cold," he said over the weekend, according to CNN affiliate YTN.

"I thought that abandoning the ship without discretion would make you drift off a fairly far distance and cause a lot of trouble. At the same time, the rescue ship did not come, and there were no fishing boats or supporting ships around to help at that time."

But the first mate of a boat that responded to the Sewol's emergency call disagreed.

"If the passengers had jumped into the water sooner, more people could have been rescued," Eun Dae-young told CNN affiliate YTN in a phone interview Monday.

The ferry captain has been charged with abandoning his boat, negligence, causing bodily injury, not seeking rescue from other ships and violating "seamen's law," South Korean media reported.

Prosecutor Lee Bong-chang gave more details about the accusations against the captain.

"Mr. Lee is charged with causing the Sewol ship to sink by failing to slow down while sailing the narrow route and making (a) turn excessively," the prosecutor told the semiofficial Yonhap news agency.

"Lee is also charged with failing to do the right thing to guide the passengers to escape and thereby leading to their death or injury."

If convicted, the captain faces from five years to life in prison.

The captain wasn't at the helm of the Sewol when it started to sink, the prosecutor said. A third mate was at the helm.

Authorities said Monday that four more crew members of the ferry have been detained, bringing the total number arrested to seven.

Two first helmsmen, one second helmsman and the chief engineer are now under arrest, said Yang Joong-jin, the chief prosecutor of the investigation. He said the four crew members could face indictment on several charges.

As well as the captain, two other crew members were arrested over the weekend.

Divers feel emotional strain

Dozens of divers have continued to plunge into the frigid, murky waters, still holding out hope that they might find somebody alive inside the sunken ship.

"There must be survivors, no matter what we must find the air pocket. That's why I have hope," Choung Dong-nam, the head of volunteer divers involved in the search, said Sunday.

But each hour reduces the chances of finding anyone alive, and the human cost of the disaster weighs on the divers.